package adv1;

public class Test {

	public static void main(String[] args) {
		// System.out.println();
		long time = System.currentTimeMillis();
		System.out.println(time);
		long start = System.nanoTime();//
		int k = 0;
		for (int i = 1; i <= 100; i++) {
			k += i;
		}
		long end = System.nanoTime();
		System.out.println("for循环花了" + (end - start) + "毫微秒");
		System.out.println("当前配置信息：");
		System.out.println(System.getenv());
		System.out.println(System.getProperties());

		int[] a1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
		int a2[] = new int[20];// 从a2的第五个开始复制，全部把ar复制过去
		System.arraycopy(a1, 3, a2, 4, 5);
		for (int f : a2) {
			System.out.print(f + " ");
		}

		// for (int i = 0; i < a1.length; i++) {
		// a2[i] = a1[i];// 复制过去
		// }

	}

}
